A method for assessing the print result of an ink-jet printing device and printed support means having a calibration element

Abstract

A method comprises the steps of: providing an ink-jet printing device; providing print support means ( 100; 200; 300; 400 ); printing a calibration element on the print support means ( 100; 200; 300; 400 ) using the ink-jet printing device, by moving the print support means ( 100; 200; 300; 400 ) and the ink-jet printing device with respect to one another along an advancement direction (F), using a measurement device, carrying out a plurality of partial measurements of respective parts of the calibration element printed on the print support means ( 100; 200; 300; 400 ); calibrating the ink-jet printing device by combining information obtained during the partial measurements.

1 - 18 . (canceled) 
     
     
         19 . A method comprising the steps of:
 providing an ink-jet printing device;   providing a print support arrangement delimited by a print surface;   printing a calibration element on the print support arrangement using the ink-jet printing device, by moving the print support arrangement and the ink-jet printing device with respect to one another along an advancement direction,   using a measurement device, carrying out a plurality of partial measurements of respective parts of the calibration element printed on the print support arrangement;   calibrating the ink-jet printing device by processing information obtained during the partial measurements,   wherein the calibration element has dimensions larger than the dimensions of the maximum image acquisition area of the measurement device and wherein in order to calibrate the ink-jet printing device there is provided reconstructing the calibration element by combining information obtained from the partial measurements of said parts of the calibration element which has been printed on the print support arrangement, the partial measurements being carried out by positioning the measurement device on a region of the print surface and acquiring the image of one of said parts of the calibration element, moving the measurement device at another region of the print surface and acquiring the image of the corresponding part of the calibration element, and so on until the entire calibration element has been measured.   
     
     
         20 . The method according to  claim 19 , wherein, during the step of printing the calibration element, at least one part of a virtual image of the calibration element is printed, the virtual image comprising a plurality of portions of the calibration element, said plurality of portions comprising at least a first portion and at least a second portion offset with respect to one another, an edge of the first portion which extends parallel to the advancement direction being aligned to an edge of the second portion. 
     
     
         21 . The method according to  claim 20 , wherein the plurality of portions comprises a plurality of first portions arranged along a first line and a plurality of second portions arranged along a second line, the first line and the second line extending transversally to the advancement direction, the first portions arranged along the first line being offset with respect to the second portions arranged along the second line. 
     
     
         22 . The method according to  claim 20 , wherein the print support arrangement comprises a single print support on which the entire virtual image of the calibration element is printed. 
     
     
         23 . The method according to  claim 20 , wherein the print support arrangement comprises a plurality of print supports, a part of the virtual image of the calibration element being printed on each print support. 
     
     
         24 . The method according to  claim 23 , wherein a single portion of said plurality of portions of the virtual image of the calibration element is printed on each print support. 
     
     
         25 . The method according to  claim 23 , wherein an incomplete portion of the plurality of portions is printed on at least one print support, said incomplete portion being included in a portion which is entirely printed on a further print support of the print support arrangement. 
     
     
         26 . The method according to  claim 20 , wherein each portion comprises a plurality of coloured regions arranged in a sequence along the advancement direction, each coloured region comprising at least one line of patches which have a constant printing density along a direction perpendicular to the advancement direction and a printing density gradually increasing or decreasing along the advancement direction. 
     
     
         27 . The method according to  claim 20 , wherein graphic reference signs are printed on the surface of the print support arrangement, the graphic reference signs being arranged outside the portions and being usable for localising a portion of the calibration element which can be measured by the measurement device. 
     
     
         28 . The method according to  claim 21 , wherein a non-printed area is interposed between two first portions arranged along the first line, and between two second portions arranged along the second line. 
     
     
         29 . The method according to  claim 19 , wherein the calibration element comprises at least one coloured region which has a width, measured perpendicularly to the advancement direction, equal to the maximum width printable by the ink-jet printing device. 
     
     
         30 . The method according to  claim 29 , wherein the calibration element comprises plurality of graphic reference signs arranged upstream and/or downstream of said at least one coloured region with respect to the advancement direction, the graphic reference signs being absent outside the width of said at least one coloured region. 
     
     
         31 . The method according to  claim 19 , wherein the ink-jet printing device comprises a plurality of printing heads and wherein the step of calibrating is directed at making uniform the quantity of ink emitted by the printing heads, for a preset amount of ink requested to each printing head. 
     
     
         32 . A print support having a surface on which a plurality of portions of a calibration element is printed, each portion of said plurality of portions being formed by a plurality of patches, said plurality of portions comprising at least a first portion of the calibration element and at least a second portion of the calibration element offset with respect to one another, an edge of the first portion which extends along a direction being aligned with an edge of the second portion adjacent to the first portion, wherein the plurality of portions comprises a first line of first portions and a second line of second portions, the first line and the second line extending transversally to said direction, the first portions arranged along the first line being offset with respect to the second portions arranged along the second line, a non-printed area being interposed between two first portions arranged along the first line, and between two second portions arranged along the second line, wherein graphic reference signs are printed on the surface of the print support, the graphic reference signs being arranged outside each portion for localising a portion of the calibration element which can be measured by a measurement device. 
     
     
         33 . A print support having a surface on which at least a first portion of a calibration element is printed and at least one part of a second portion of the calibration element is printed, said at least a first portion and said at least one part of the second portion being offset with respect to one another, an edge of said at least a first portion which extends along a direction being aligned with an edge of said at least one part of the second portion adjacent to said at least a first portion. 
     
     
         34 . Print support arrangement comprising a plurality of print supports on each of which a portion of a calibration element is printed, an identification number being printed on each print support and associated to the corresponding portion of the calibration element, the identification number being intended to identify the calibration element after a plurality of patches of each portion have been measured by a measurement device, wherein each portion of each print support is furthermore surrounded by graphic reference signs for localising said portion.